Process of inducing toxicity and product thereof



Patented Nov. 21, 1944 raocass OF INDUCING TOXICITY AND PRODUCT THEREOFJacquelin E. Harvey, Jr., Washington, D. C., and Robert H. White, Jr.,and Joseph A. Vaughan. Atlanta, Ga., assignors of one-half tosaidHarvey, Jr., and one-half to Southern Wood Preserving Company, EastPoint, Ga., a corporation of Georgia No Drawing. Original applicationNovember 18, n 1942, Serial No. 466,054. Divided and thisapplication'November 23, 1943, Serial No. 511,481

10 Claims.

The instant invention relatesto the production of toxic oils employableas fungicides, insecticides, and for any other service to which toxicoils may be put, being a division of our application Serial No. 466,054,filed November 18, 1942, for Method of producing valuable materials andproducts thereof.

More especially the instant invention relates to the production of toxicoils from mixtures of petroleum fractions characterized by ringstructure content. Among such starting materials may be mentionedmixtures of petroleum fractions characterized by ring structure contentrecovered from petroleum fractions by well known extraction methodsincluding extractive distillation and azeotropic distillation. Also maybe mentioned mixtures of petroleum fractions characterized by ringstructure content as flowing from thermal and/r catalytic treatment ofcertain petroleum fractions which includes petroleum fractions havingring structures induced in the course of thermal and/or catalytictreatment, as for example having ring structures induced in the courseof one or more thermal and/or catalytic treatments of unusual length, asfor example, for periods of from 1-10 hours or more.

An object of the instant invention is the production of toxic oils fromthe aforenamed petroleum fractions 01 others whereby to provide oils ofthe preservative type, as for example preservative wood impregnantsconforming to specifications extant or acceptable to the trade consumingsuch oil materials.

Another object of the instant invention is the provision of preservativewood impregnants having boiling ranges and residues in accordance withpublished specifications and/or in accordance with consumer preference.

Another object of the instant invention is the reforming, modifying,converting and/or trans-,- forming of the mixtures of hydrocarbonswhereby to induce toxicity.

Still another object of the instant invention is the induction of usabletoxicity in the presence of a gas or gaseous mixtures. 7

.Another object of the instant invention is the unveiling of latenttoxicity in mixtures of petroleum fractions having inherent butinhibited toxicity.

Another object of the instant invention is the maintenance of apreponderant proportion of the cyclic structures in the materialundergoing toxicity induction in at least a methylated condition, ithaving been found that. objectionable reaction products are formed ifthis object is not adhered to.

Another object of the invention is the control of saturates in specificfractions of the material undergoing treatment.

Still another object of the instant invention is the control of thepercentage of cyclic structures, as for instance aromatics, in specificfractions of the beneficiated material which is characterized by inducedtoxic properties.

Yet another object of the instant invention is the provision in theoverall beneficiated material of that percentage of newly inducedfractions boiling below 210 C. which is conducive to the induction oftoxicity in other fractions of the material under treatment.

Another object of the instant invention is a change in specific gravityin the overall beneficiated material which is conducive to the inductionof toxicity.

Another object of the instant invention is the coordination of .processvariables so as to provide specific gravities within definite limits invarious fractions of the beneficiated material.

Another object of the instant invention is a coordination of processvariables which will provide in various fractional parts of thebeneficiated.

material cyclic structures with specific gravities falling within thelimits hereinafter stated.

Another object of the instant invention is the induction of toxicity inthe presence of a reforming catalyst adapted to favorably influence theinduction of toxicity. By the expression a reforming catalyst is meant acatalytic material adapted to exert catalytic influence whilst thestarting material is being reformed, transformed, modifiedand/orconverted. In the specification and in the annexed claims,reformation,

transformation, conversion and/or modification of the starting. materialwhereby to induce toxicity is specifically meant to include cracking,addition, and substitution reactions that are possible within the limitsof the process variables disclosed elsewhere herein.

Another object of the instant invention is the induction of additionaltoxicity into fractional parts of the once beneficiated startingmaterial under specific controls of process variables.

In the past Wood preservative oils of the high temperature coal tarderived type have been employed in quantities greatly exceeding thetotal of all other wood preservative oils. From the standpoint ofavailability of said coal tar as the parent product of wood preservativeoils, it is annually produced in this .country under normal conditionsto the extent of five hundred million to six hundred million gallons.This quantity of coal tar is capable of yielding an amount of highlyeffective wood preservative oils which would make this countryself-sufficient in its wood preservative requirements. However, due

to the fact that when a wood preservative dlstillate (creosote) isrecovered from coal tar there remains in the still a residue (pitch)which, at best, is a low priced product and which, at worst,

is a seriously distress product to the end that at v times it is placedin inventory rather than $0151.

The current method of processing coal tar leaves much to be desired. Thenet result of this situation obtaining is that the coal tar distillerusually confines himself to that distillation recovery of creosote whichwould correspond to the attending amount of pitch that he can market ata profit. Accordingly, over a period of years several hundred milliongallons of creosote oil have been imported into this country. That sucha situation should obtain is apparently a paradox in that we annuallyproduce a quantity of high temperature coal tar which if processed toyield creosote would make us self sufllcient in that re- 4 quirement. Asurvey of this paradox is fully outlined in. an address given by no lessan authority than S. P. Miller, technical director, The Barrett Company,40 Rector Street, New York city, before the Franklin Institute,Philadelphia, Pennsylvania, in December, 1932. The economics of 7 coaltar have not materially changed since that date.

In view of the apparent inability of the coal 1 tar industry to providenational needs of wood Oil Company and which has the followinginspection:

Gravity 10.8 Flash, P. M. C. C F..- 295 Flash, C. O, C F-.. 290 Fixedcarbon "per cent-.. 4.9 Pour point 4---- F-.. -10 B. S. & W per cent byvolume. 0.1 S. U. vis 100 F 151 S. U. vis. 210 F 41 S. F. vis. 77 F 34.5Carbon residue 6.8 Per cent aromatics and unsaturates 82.4 Sol. in CS299.8 Loss 50 grams, hours, 325 F 8.9 Residue of 100 pene per cent 37.5

A. S. T. distillation:

I. B. P., F 518 rec. @F 565 rec. F 589 rec. F 614 40% rec. F 637 50%rec. F 660 1 675 0% rec. F

1 Maximum.

In the foregoing tabular data P. M. C. 0. means Pensky- Martin ClosedCup; C. O. C. means Cleveland Open Cup.

Upon evaluating the foregoing oil for its toxicity to wood destroyingfungi (Madison 517), it was found that this oil did not inhibit thegrowth of the fungi named at a concentration of up to and including 10%.

, It is now discovered that the oil above named or other oils of cyclicstructure content produced by the petroleum industry can be increased intoxicity in accordance with the process of the instant invention.

According to the instant invention 0115 of cyclic structure contentproduced by the petroleum industry are reformed, transformed, modifiedand/or converted to oils of a more toxic nature clude mixtures ofpetroleum fractions characterized by cyclic content and includesspecifically various forms and types of naphthenes found in variousmixtures of petroleum fractions, as for example monocyclic andpolycyclic naphthenes.

The so-called petroleum aromatics which includes the monocyclic andpolycyclic naphthenes and unsaturated hydrocarbon fractions have in thepast been produced in very large quantities. However, very little workhas been done on these materials; Such a fact is borne out on page 667,Reactions of pure hydrocarbons Gustav Egloff, Reinhold PublishingCorporation, 330 West 42nd Street, New York city, which states:

Despite the fact that napthenes or cycloparafiines are available inenormous quantities, as shown by an estimate of 100,000,000 barrelspresent in the 1,498,000,000 barrels of crude oil which was the worldsproduction in 1934, comparatively little work of a pyrolytic nature hasbeen performed on individual naphthene hydrocarbons or the cycloolefins.

Several oils of cyclic structure content produced by the petroleumindustry have been inspected for their toxicity to wood destroyinghaving characteristics acceptable to consumers of wood preservativeimpregnant and/or conforming to wood preservative specifications extant.

The following examples will serve to illustrate several modes ofpracticing the present invention.

Example 1.--A mixture of petroleum fractions characterized by cyclicstructure content having but slight growth inhibition to wood destroyingfungi, as for example the Shellproduct shown in the foregoing tabulardata, is charged to a vessel adapted to operate at superatmosphericpressure, as for instance at a pressure as high as several hundredatmospheres. The catalyst is a reforming catalyst. The oil is brought upto a temperature of 430 C. wherein it is held in the commonly acceptedliquid phase at a pressure of 850 pounds for such a length of time as toprovide 20% newly formed fractions boiling below 210 C.

At the end of the stated period the oil is withdrawn from the processingchamber, cooled and inspected. Upon inspection the oil is found to havetoxic properties unveiled as the result of the treatment above named,and such induction of toxicity is accompanied and evidenced by theproduction of the named percentage of newly in- Toapproximate commercialoperating condi tions it is preferred to so control process variables asto provide about 35% newly formed materials boiling below 210 C., and inthis manner of. operation pronounced toxicity is'induced.

In the induction of toxicity in accordance with the instant method, theProcess variables are so coordinated as to maintain a preponderantproportion of the cyclic structures of the materials under treatment inat least a methylated condition, it having been found that an attempt tototally dealkylate the cyclic structures of the starting materialresults in the formation of toxicity diluents, inordinate gasificationand/or the formation of substantially non-toxic substances. Theexpression in at least a methylated condition refers to the numberofcarbon atoms in the ring appendages. Each fraction of the beneficiatedmaterial of induced toxicity, as for example and especially thematerials boiling between 315 C. and 355 C., has a preponderantproportion of materials of cyclic structure present in at least amethylated condition.

Conditions that are prejudicial to the maintenance of a preponderantproportion of the cyclic structures of the starting material in at leasta methylated condition are excessive temperatures and/or excessive timeof treatment. Temperatures that are employable in the instant processwhich will provide the aforenamed endresult are selected between thelimits of SOD-550 C.,:and preferably between 400-500 C., say-430 C. to480 C. Using the preferred temperature whilst operating atsuperatmospheric pressure, as for example at pressuresranging between400- 3000 pounds, it will be found that when the treatment is carried onfor a period of one to two hours the end product will have inducedtoxicity as flowing from, among other things, the maintenance of apreponderant proportion of the materials of ring structure content ofthe starting material in at least a methylated. condition,

-. and accompaniedwith and: indicated by-a perc'centage of newly formedfractions boilingbelow 210 C. falling between the'limits of about 10-50%, and the induction of toxicityis enhanced by the specific inclusionof a reforming catalyst.

The pressure employed in the instant process may be autogenous due tothe pressure of evolved vapors, or the pressure may be provided by anybilized residual, distillate or extract and in the event the extract hasnon-permissible low boiling ends, the extract may be stabilized to thenecessary or desired extent.

As examples of wood preservative impregnants of the oil derived typethat are meeting with consumer preference and which may be produced orparalleled by the process of the present invention, the followingtabular data show several published specifications:

Woon PRESERVATIVE IMPREGNANTS Specifications 1. American Wood PreserversAssociation a. Up to 210 C., not more than 5% i b. Up to 235 C., notmorethan 25% g 2. American Wood Preservers Association a; Up to 210 C., notmore than 1% b. Up to 235C not more than 10% c. Up to 355 C., not lessthan 65% 3. American Wood Preservers Association a. Upto 235C, not morethan 1 b. Up to 300 C.," not-more than Ni 0. Up to 355 C., not less than45% 4. American Wood Preservers Association 0. Up to 210 C., not morethan 8% 0. Up to 235 C., not more than 35% 5. American Wood PreserversAssociation a. Up to 210 C., not morethan 10% 17. Up to 235 C., not morethan 40% 6. American Wood Preservers'f Association a. Up to 210 C., notmore than 5% b. Up to 235 C., not more than 15% '7. Prussian Ry.

(1. Up to 150 C., not more than 3% .17. Up to 200 C., not more than 10%0. Up to 235 C., not more than 25% 8. National Paint Varnish & LacquerAssociation #220 1.5% at 162 C. b. 97% at 270 C.

9. Southern pine shingle stain oil a. 5% at 137 C.

b. at 257 C.

10. Neville shingle stain oil a. I. B. P., C. 11.5% at 205 C. 0. 95% at292 C.

11. Carbolineum ..270 c., I. B. P.

If desired, the processing of the oil may be carried on m the presenceof an extraneous gas whose partial pressure may vary over wide ranges,as for example the partial pressureof the extraneous gas may be 5-50% ormore. Among the extraneous gases employable are hydrogen, carbonmonoxide, carbon monoxide and water vapors, methane and its homologues,various refinery gases and inert gases such as nitrogen and carbondioxide. Certain special benefits fiow from carrying on the toxicityinduction in the presence of an extraneous gas, among which may bementioned the thermal protection of the material under treatment, as forexample when employing hydrogen or a hydrogen containing gas thematerial under treatment is not so susceptible to polymerizingreactions. This provision, in one mode of operation is to bespecifically read into the foregoing example, and in the event it In theevent it is elected to employ carbon monoxide and water, the totalpressure may vary over wide limits, as for example from 200 to 5,000pounds, or higher. In like manner the carbon monoxide partial pressuremay vary over wide limits, as for instance, from 51.0 50 percent, orhigher. The water may represent from 5 to 50% or higher based on the oilunder toxicity inducing conditions, and in some instances may representmore than twice the amount of the charged oil. In one mode of operation,this deflnite teaching concerning the employment of carbon monoxide andwater is to be specifically read into all examples. The carbon monoxideand water may be introduced simultaneously with the feed stock, or atother times, separately or jointly.

Example 2.--A liquid sulfur dioxide extract is charged to a highpressure autoclave and hydrogen pumped into an upper pressure of 1,000pounds. Threeper cent of a reforming catalyst is employed. The materialis heated to a temperature of 450 C. and held at that heat tone for aperiod of one hour and minutes. A maximum pressure of 2050 pounds isattained when a heat tone of 425 C. is reached.

At the end of the named processing period, the oil is, discharged fromits treating enclosure, cooled and inspected. It is found that 19.2%newly formed materials boiling below 210 C. have been formed, and thebeneficiated oil requires a smaller concentration for a-given growthinhibition of wood destroying fungi than the starting material. It isalso determined that a preponderr ant proportion of the materials ofcyclic structure content in the treated oil has been maintained in atleast a methylated condition.

The overall beneficiated material may be used as a preservativeimpregnant of induced toxic properties, or a preservative impregnant ofthe desired boiling range'may be segregrated therefrom.

Example 3.Another mode of practicing the instant process whereby toinduce toxic properties resides in the control of saturates in thebeneficiated material boiling above 270 C., as for example the materialboiling between 270 C. and

It has been determined that the materials boiling above 270 C. in thebeneficiated oil have a relatively low toxicity as compared to materialsboiling below that temperature. It is known that unsaturates are amongstthe most toxic of oil substances. However, it isalso determined that ifan attempt is made to provide in the, beneboiling above 270 C., as forexample in the materials boiling between 270 C. and 355 C., to less than30% but more than 5%, and preferably not more than 10%, no operatingills such as above named will occur, or if said ills do occur they areminimized.

As an illustrative control of process variables which provides inducedtoxic properties whilst yielding an oil having less than but more than5% saturates in the materials boiling between 270 C. and 355 C., thefollowing opernamed period of treatment the beneficiated oil isdischarged from its treating enclosure, cooled and inspected. Thebeneficiated oil has only 28.5% residue above 355 C. and it isdetermined that there are only 23.3% and 12% saturates, respectively, inthe 270-315 C. and 315-355 C. fractions. The oil has toxic propertiesthat are more pronounced than the parent feed stock. During the courseof treatment 18.1% of newly formed materials boiling below 210 C. wereformed. A further inspection of the beneficiated material discloses thata preponderant proportion of the cyclic structures of the startingmaterial was maintained in at least a methylated condition.

A variation of the process described in Example 3 may be provided bycarrying on the process in the absence of hydrogen, and certain toxicitybenefits will flow therefrom. The provision of carrying on the processwithout protective gas of extraneous source is, in one mode ofoperation, to be specifically read into Example 3.

Example 4.-An oil of cyclic structure content produced by the petroleumindustry having inherent but inhibited toxicity, an initial boilingmatics, as. for example aromatics having side point of about 270 C.,about 50% residue above 355 C. and 52% and'54% aromatics, respectively,in the 270315 C. and 315-355 C. fractions, is subjected to a liquidphase thermal treatment in the presence of a reforming catalyst andhydrogen at a temperature of 455 C. fora period of one hour and 30minutes. At the end of the named period the treated oil is withdrawnfrom the processing enclosure, cooled and inspected. It is found thatabout 22% newly formed fractions boiling below 210 C. have been formed.

The residual matters above 355 C. have been reduced by in excess of 45%.The fractions of the beneficiated material boiling between 270-315 C.and 3153 55 C. have 71% and 80.5% aromatics, respectively. The overallbeneficiated oil is characterized by a toxicity more pronounced than thestarting material.

It is well understood in the art that the arochains not longer than thepropyl group are amongst the most toxic of all substances. As stated inthe foregoing, the feed stock in the instant example has slightly morethan 50% aromatics in the 270-355 C. fraction. However, the aromaticspresent, due to their peculiar type, exhibit inhibited toxicity. Itwould then, therefore, appear reasonable to attempt to provide in thefinally beneficiated oil total aromaticity in the materials boilingbetween 270 C. and 355 C. in order to induce toxicity of a highorder,and more especially it would appear reasonable to attempt to providetotal aromaticity of a type exhibiting satisfactory toxic values. It isdiscovered, however, that if an attempt is made to provide in thebeneficiated material the entirety of the materials boiling above 270C., as for example the materials boiling between 270 C. and 355 (3., asaromatics, either of the toxicity-inhibited or toxicity-uninhibitedtype, adverse reactions occur which are prejudicial to a satisfactoryinduction of toxicity, as for example there occurs 1) inordinategasification, (2) inordinate production of materials of relatively lowtoxicity and/or (3) high boiling polymerized materials.

It is found that by holding the percentage of aromatics in the materialsboiling above 270 C. in the beneficiated oil, as for example theheneficiated materials boiling between 270 C. and 355 C., to more than70% but less than 95%. and preferably not less than 90%, toxicity isinduced in a commercial manner with the added benefits that theoperating ills above mentioned are minimized or eliminated.

The oil of the instant example, as stated in the foregoing, has toxicproperties more pronounced than the parent feed stock, and may be usedin toto as a preservative wood impregnant. This phase of the instantinvention, in any and all examples, resides 'in the novel manner ofinducing toxic properties without reference to the provision ofspecification oils. However, as also previously mentioned, specificationoils may be segregated from the overall beneficiation.

In lieu of practicing the process as specifically provided in Example 4,the process, in one mode of operation, may be specifically carried onwithout the presence of a protective gas of extraneous source and anincrease of toxicity will fiow from this mode of practice. However, theincrease of toxicity when provided by thermal treat ment in the absenceof a protective gas is not as satisfactory as when carried on in thepresence of the protective gas.

Example 5.Another mode of practicing the instant process resides incontrolling the specific gravity of the overall beneficiated materialremaining finally liquid after completion of impressed processvariables.

It has been found that if an oil mentioned in the foregoingcharacterized by inherent but inhibited toxicity is subjected to thermaltreatment in the presence of a reforming catalyst, with or without aprotective gas of extraneous source, whereby to provide a beneficiatedmaterial remaining finally liquid having, ascompared to the parent feedstock, an overall change in specific gravity between 0.015 and 0.15, andpreferably between 0.020 and 0.10, the material of the changed specificgravity has toxic properties more pronounced than the parent feed stock.a

Thi change in specific gravity is a valid test for induced toxicity.The'noted change in specific gravity which is conducive to the inductionof toxic properties may be either up or down, as more fully disclosedand explained "in the follow- An oil of induced cyclic structuresproduced by the petroleum industry havinga specific gravity of 0.960.characterized by inherent but inhibited toxicity, boiling preponderantlyabove 315 C. and with substantial residual matter above 355 C., issubjected to a liquid phase thermal treatment in the presence of areforming catalyst and a hydrogen" containing gas at a temperatureof'465 C. whilst under a pressure of 1500 pounds for a period of twohours. At the end of the named treatment period the oil is cooled andinspected and found to have a specific gravity of 0.940 or a reductionin specific gravity of 0.020%. The overall beneficiated material hasinduced toxic properties and more than 10% but less than 50% newlyformed fractions boiling below 210 C.

According to this specific mode of operational control and test in theinstant example, the process variables are so coordinated as to cause areduction in specific'gravity falling between the limits of 0.015 and0.15%, and preferably between 0.020% and 0.10%. Such a stated change inspecific gravity has the effect of inducing and indicating the inductionof toxic properties into materials previously having inhibited toxicvalues. The lowering of the specific gravity within the defines statedis critical within limits. less an overall specific gravity of thematerial under treatment is lowered by 0.015%, a certain unveiling ofinhibited toxicity is sacrificed, and if the overall specific gravity islowered by more than 0.15%, inordinate gasification, production offugitive materials of relatively low toxic valuef and/or polymerizationwill occur. To avoid or minimize these ills, and/or others, thereduction of specific gravity is preferably held between 0.020% and0.10%.

Certain toxicity benefits will fiow from carry ing on the process ofExample 5 without the inclusion of the protective gas of extraneoussource. In one mode of operation, this provision of carrying on theprocess without a protective gas of extraneous source is to bespecifically read into that part of Example 5 which provides for thelowering of the overall specific gravity of the feed stock. i

In connection with the change in specific gravity of the overallstarting material which results in the induction of toxicity, amodification of the process resides in raising the specific gravity ofthe material remaining finally liquid after impressed process variablesby a percentage falling between the limits of 0.015 and 0.15, andpreferably between 0.020 and 0.10.

To illustrate this modification of the instant process an il of cycliccontent produced by the petroleum industry having relatively littletoxicity, as for example a flashed residuum having a specific gravity of0.924 and a substantial percentage of materials boiling above 355 C. issubjected to a liquid phase thermal treatment in the presence of areforming catalyst and a saturated hydrocarbon gas at a temperatureselected between the limits of 450-525 C. whilst under a pressure of1200 pounds for such a period of time as to provide an overallbeneficiated material remaining finally liquid having a speciflc'gravityof 1.015. When the stated specific gravity has been attained thebeneficiated material will have substantial residual m'atter above 355C. A period of from one to five hours dependent upon 1 the temperatureselected will illustratively serve for the stated increase of specificgravity.

The oil of the stated increased specific gravity is inspected and foundto have toxic properties more pronounced than its parent feed stock. Thebeneficiation in toto may be used as a preservative wood impregnant or,as taught in the foregoing, animpregnant of induced toxic propertieshaving a specification boiling range may be segregated therefrom.

In lieu of increasing the specific gravity whilst employing a gas ofextraneous source, the process may, in one mode of operation, be practiced without the added gas. When increasing the specific gravity withthe exclusion of an extraneous gas, the increase of the specific gravityis held within the limits noted in the foregoing.

Example 6.-An oil containing materials of cyclic structure contentproduced by the petroleum industry, as for example a liquid sulfurdioxide or furfural. extract, having inherent but inhibited toxicity,boiling 15% at 315 C., and about 45% residual matter above 355 C., ischarged to a high pressure autoclave and subjected to a liquid phasethermal treatment in the presence of a reforming catalyst and water gasat a temperature selected between 435-485 C. whilst under a pressure of1700 pounds for such a time as to jointly provide more than 10% but lessthan 50% newly formed fractions boiling below 210 C., and an overallspecific gravity in fractional parts of the beneficiated oil fallingwithin the limits noted in the following tabular data:

Fractions Low limit High limit and preferably between the limits notedbelow:

' Fractions Low limit High limit hibition of wood destroying fungi thanthe starting material.

The overall beneficiation may be used as a preservative wood impregnant,or there may be segregated therefrom an -oil complying withspecifications extant, as for example an oil complying With the boilingrange of a carbolineum type preservative oil, which in some instancesboils almost entirely above 270 C.

The specific gravities of fractional parts of the beneficiated materialnoted in the foregoing are critical within limits. "Unless the lowerlimit is approximated toxicity unveiling will be sacrificed. If the highlimit is substantially exceeded adverse reactions will occur, as forexample there will be inordinate gasiflcation and/or produc tion ofhighly polymerized and objectionable materials.

Instead of practicing the process disclosed in the immediate example byemploying a protective gas of extraneous source, this mode of operationmay be carried on without a gas of extraneous source with the resultantapproximation of the noted specific gravities. Induced toxicity willalso flow from the practice of this process variation.

Example 7.In lieu of inducing toxicity whilst providing operationalcontrol of the overall specific gravity of fractional parts of thebeneficiated material as heretofore disclosed, the control may be gaugedby the provision of predetermined speciiic gravities of materials ofcyclic structure content in fractional parts of the beneprovide morethan 10% but less than 50% newly formed fractions boiling below 210 C.,and a specific gravity of materials of cyclic structure content infractional parts of the beneficiated material falling between the limitsnoted in the following tabular data:

' Fractions Low limit High limit and preferably between the limits notedbelow:

Fractions Low limit High limit 210-235 0. 0.941 1. 0430 235270 o 0.963 1. 0606 270315 o 1.001 1.0783 3l5355 o 1. 055 1.1135

The provision of specific gravities of materials of cyclic structurecontent in fractional parts of the beneficiation noted in the foregoingis critical within limits. Unless the lower limit is approximatedtoxicity induction is sacrificed. If the high limit is exceeded adversereactions will obtain, as for example there will occur inordinategasification and/or production of highly polymerized materials.

In the mode of operation which induces toxicity whilst providing thestated increase of specific gravities in the materials of cyclicstructure content, this process variation may be specifically practicedwithout the protective gas of extraneous source.

Example 8.Referring specifically to the overall beneficiated material ofinduced toxic properties produced by the process variations of theforegoing'examples, it is found that the materials boiling below andabove 270 C. have relatively high and low toxicities. respectively. Itis discovered that additional toxicity may be induced into thebeneficiated material by subjecting same to another toxicity inducingcycle at a higher temperature than obtained in the first cycle oftoxicity induction provided the retreatment yet maintains a preponderantpercentage to the overall once beneficiated material of Example 1, thisbeneficiation is subjected to another toxicity inducing cycle in theliquid phase in the presence of a reforming catalyst and hydrogen at atemperature of 450 C. whilst under a pressure of 850 pounds. Theretreatment is continued for a period of 45. minutes. The stated periodis illustrative only. The re treatment period is desirably that whichprovides in the finally rebeneficiated material less than 50% newlyformed materials boiling below 210 (2., including the fixed gas orgases, based on the starting material. At the end of the stated periodthe retreated material is withdrawn from its treating enclbsurecooled,inspected and found to have toxic properties in excess of the overallonce beneficiated oil. It is also determined that the finallybeneficiated material yetmaintains a preponderant proportion of thecyclic materials in at least a methylated condition.

When retreating the overall once beneficiated material, the process mayspecifically be carried on without theinclusion of the protective gas ofextraneous source, and toxicity benefits will flow from this practice. l

Example 9.-In lieu of retreating the entirety of the once beneficiatedmaterial at a more elevated temperature, only a portion thereof may beretreated in the liquid phase in the presence of a reforming catalyst,with or without the presence of a protective gas of extraneous source,and certain definite toxicity increases and benefits will flowtherefrom, as for exampleby retreating in liquid phase only thematerials of relatively low toxicity boiling above 270 C. Or; theretreatment of materials boiling above 270 C., or a portion thereof, maybe effected at the same temperature as the initial treatment. When thematerials of relatively low-toxicity are retreated for added toxicityinduction at either of the temperatures aforenamed', the retreatedmaterial when commingled with that portion of the starting material oncebeneficiated, will provide acomminglement having toxic properties inexcess of those of the once treated oil.

Example 18.-Practice the process of Example 9 with the coprecipitatedoxides of copper and chromium as catalytic materials.

ExampZe19.-Practice the process of Example 1 with tin chloride ascatalytic material.

Example 20.Practice the process of Example 2 with aluminum chloride ascatalytic material.

Example 21.--Practice the process of Example 3 with iodine as catalyticmaterial.

Example 22.Practice the process of Example 4 with iodoform as catalyticmaterial,

Example 23.-Practice the process of Example 5 with hydroiodic acid ascatalytic material,

Example 24.--Practice the process of Example 6 with chlorine ascatalytic material.

Example 2'5.-.-Practice the process of Example 7 with bromine ascatalytic material.

Example 26.-Practice the process of Example 8 witha hydrogen halid ascatalytic material.

Example .27.-Practice the process of Example 4 with a silica hydrogelimpregnated with an aluminum salt as catalytic material.

Example 32.-Practice the process of Example 5 with bentonite and anadsorptive clay as cat- I 6 with a siliceous material impregnated with aI metallic oxide as catalytic material.

Instead of commingling the entirety of the once treated materials andthe twice treated materials, only a portion thereof maybe commingledprovided the comminglement furnishes an oil conforming in boiling rangeto consumer acceptance or provides a comminglement from which may besegregated an oil of consumer acceptance. I

The retreatment temperatures are selected between the limits of 300-550C. and. preferably.

between 425-500" C.

Example 10.-Practice the process of Example 1 with a molybdenum oxidecatalyst.

Example 11.Practice the process of Example 2 with a chromium oxidecatalyst.

Example 12.-Practice the process of Exam- Example 16.-Practice theprocess of Example 7 with a vanadium sulfide catalyst.

Example 17.--Practice the process of Example a with a tin sulfidecatalyst.

Example 34.-Praotice the process of Example? with a silicious materialimpregnated with a metal sulfide as catalytic material.

-Example35.-Practice the process of Example 8 with coprecipitatedalumina and chromi'a hydrogels as catalytic materials.Example36'.---Practice'the process of Example 9 with a syntheticsilica-alumina gel as catalytic material.

The various catalysts mentionedin the foregoing assist in the reforming,transforming, modifying and/or converting. of the starting petroleurnoils whereby to providematerials ofinduced tution and addition productsthereof. as for example and specifically substitution andadditionproducts of said derivatives, say a hydrogen halid.

The temperatures of the instant process, in anv and all steps, areselected between the limits of BOO-550 C.. and preferably between425-500" C.

The pressures employed in the instant process are in excess ofatmospheric and are specifically those pressures required for operationin the liqrid phase. The term liquid phase may not be technicallycorrect, but as used herein and in the annexed claims is meant'todistinguish from the containing gas.

so-called' vapor phase operation which employs vaporized materials only,v

If desired, instead of subjecting the entirety of the feed stock to asingle toxicity inducing operation, the parent material may besegregated into a plurality of cuts and these plurality of cuts turecontent and/or aromatics referred to in the foregoing is secured byrecourse to the method disclosed underthe caption Neutral oils of coalhydrogenation-action of sulfuric acid, Industrial and EngineeringChemistry, volume 32, page 1614 et seq., December, 1940.

Many modes of practicing the instant process are possible. As forexample the oils of inherent but inhibited toxicity mentioned in theforegoing may be subjected to a destructive distillation under pressurein the presence of a reforming catalyst, with or without the presence ofa protective gas of extraneous source, and toxicity induced therein. Thefollowing disclosures will enable those skilled in the art to practicesuch a process, at the same time adding details which will immediatelysuggest themselves as routine and noninventive improvements.

If desired, a mixture of petroleum fractions characterized by cyclicstructure content, as for example the Shell product shown in theforegoing tabular data, having inherent but inhibited toxicity ischarged to'a still adapted to operate at superatmospheric pressure whichcommunicates with a condenser. The catalyst is selected from thematerials aforementioned. Intermediate the still and the condenser is anappropriate needle valve adapted to regulate the pressure within thestill due to the pressure of evolved vapors, or jointly due to theevolved vapors and the presence of an extraneous gas. The still is soarranged that evolved vapors are at least partially refluxed. The refluxratio may vary over wide limits and different effects flow from varyingpercentages of reflux. Air is expelled from the still during thepreliminary heating period and the needle valve then closed so as todevelop the desired pressure within the still due at least partially tothe pressure of evolved vapors. It is preferred to carry on thedestructive distillation in the presence of a protective gas ofextraneous source, as for example hydrogen or a hydrogen The needlevalve is then partially opened, and the valve aperture, heat control andreflux so coordinated as to provide a relatively, constant flow ofevolved vapors through the needle valve aperture.

Operating at a pressure of, as an example a hundred pounds or higher,say many hundreds of pounds, it is found that the oil under distillationis reformed, transformed, modified and/or converted and toxicity inducedtherein. It is also found that the temperature necessary for thedistillation of any given percentage of the feed stock is considerablyhigher than for the distillation of a comparable percentage undersubstantially atmospheric pressure.

As the distillation proceeds the temperature is gradually raised so asto maintain a relatively constant flow of distillate. The distillationis carried to the desired extent, as for example for the distillationreforming of or more of the feed stock, or the distillation may becarried to the greatest extent possible. The time necessary for thedistillation of a given charging stock will be determined by the speedof firing, percentage of reflux, etc., and the process may beillustrated by recovering 310% of the still charge per hour as materialsof induced toxic properties.

If desired, the distillate may be redistilled under a similardestructive distillation to provide additional toxic properties.

In the event it is elected to employ hydrogen as the protective gas ofextraneous source, in this or other examples, the hydrogen mayspecifically be secured from carbon monoxide and water in a well knownmanner. 7

While Examples 10 to 36 disclose the use of definite catalysts withdefinite ones of the Examples 1 to 9 inclusive, it is to be understoodthat these catalysts are interchangeable with the definite controls ofthe early examples, and any of the named catalysts or their equivalentsare usable in any of the Examples 1 to 9. The examples given, and thecatalysts linked therewith are for purposes of illustration only. 1

A very attractive form of carrying out a modified mode of the instantprocess is by inducing toxicity into the starting material in thepresence of nitrogen or carbon dioxide. Thus, one mode of operationspecifically provides for nitrogen and/or carbon dioxide as theprotectivegas or gases of extraneous source.

Minor changes within the scope of the annexed claims may be made withoutdeparting from the spirit of the invention.

We claim:

1. The process of inducing toxicity into a pctroleum derived material,which comprises: subjecting a mixture ofpetroleum fractions boilingpreponderantly above 270 0.. characterized by a substantial percentageof relatively non-toxic materials boiling above 315 0., ring structurecontent and inherent but inhibited toxicity to liquid phase crackingconditions in the presence of a reforming catalyst at a temperatureselected between the limits of about 425500 C.; unveiling toxicity inthe materials under treatment by continuing the named crackingoperationfor a period not in excess of about two hours, the period beingso selected with reference to the chosen temperature and pressure so asto provide a percentage of newly induced materials boiling below 210 C.falling between the limits of 10- 50%; securing the unveiled toxicity ina relatively high degree by a coordination of time, tem perature andpressure which provides less than about 30% but more than about 5%saturates in the beneficiated material boiling between 270 C. and 355 C.whereby to provide an overall beneficiated material having substantialresidual matter above 315 C. and a toxicity in excess of between thelimits above named.

2. The process of claim 1 with inclusion of carrying on the crackingoperation in the presence of a protective gas of extraneous source.

3. The process or inducing toxicity into a pe troleum derived material,which comprises: subletting a mixture or petroleum iractions boilingpreponderantly above 270 0., characterized by a substantial percentageof relatively non toxicmaterials boiling above 315 0., ring structurecontent and inherent but inhibited toxicity to liquid phase crackingconditions in the presence of a reforming catalyst selected from thegroup consisting of oxides and sulfides of heavy ma-' terials at atemperature selected between the limits of about 425-500 C.; unveilingtoxicity in the materials under treatment by continuing the namedcracking operation for a period not in excess of about two hours, theperiod being so selected with reference to the chosen temperature andpressure as to provide a percentage of newly induced materials boilingbelow 210 C. falling between the limits of 10-50%; securing the unveiledtoxicity in a relatively high degree by a coordination of time,temperature and pressure which provides less than about 30% but morethan about 5% saturates in the beneficiated material boiling between 270C. and 355 C. whereby to provide an overall beneficiated material havingsubstantial residual matter above 315 C. and a toxicity in excess of thestarting material; and segregating from the beneficiated material an oilof the wood preservative type having induced toxicity and an initialboiling point at least as low as about 270 C., substantial residualmaterials boiling above 315 C., and an end boiling point at least ashigh as about 355 C., the fractions 270-355 C. of the segregation havinga percentage of saturates falling between the limits above named.

4. The process of claim 3 with the inclusion of carrying on the crackingoperation in the presence of a protective gas of extraneous source.

5. The process of inducing toxicity into a pctroleum derived material,which comprises: subjecting a mixture of petroleum fractions boilingpreponderantly above 270 C., characterized by a substantial percentageof relatively non-toxic materials boiling above 315 C., ring structurecontent and inherent but inhibited toxicity to liquid phase crackingconditions in the presence of a reforming catalyst selected from thegroup consisting of halogens, halids and derivatives thereof includingsubstitution and addition products thereof and substitution and additionproducts of the latter at a temperature selected between the limits ofabout 425-500 C.; unveiling toxicity in the materials under treatment bycontinuing the named cracking operation for a period not in excess ofabout two hours, the period being so selected with reference to thechosen temperature and pressure as to provide apercentage of newlyinduced materials boiling below 210 C. falling between the limits of10-50% securing the unveiled toxicity in a relatively high degree by acoordination of time, temperature and pressure which provides less thanabout 30% but more than about 5% saturates in the beneflciated materialboiling between 270 C. and 355 C. whereby to provide an overallbeneficiatecl material having substantial residual matter above 315 C.and a toxicity in excess of the starting material; and segregating irointhe beneficiated material an oil or the wood preservative type havinginduced toxlcityand an initial boiling point at least as low as about370 C., substantial residual materials boiling above 315 C., and an andboiling point at least as high as about 355 C., the fraction 270-355 C.of the segregation having a percentage of saturates falling between thelimits above named.

6. The processof claim 5 with inclusion of carrying on the crackingoperation in the presence of a protective gas of extraneous source.

7. The process of inducing toxicity into a pctroleum derived material,which comprises: subjecting a mixture of petroleum fractions boilingpreponderantly above 270 C., characterized by a substantial percentageof relatively non-toxic materials boiling above 315 C., ring structurecontent andinherent but inhibited toxicity to liquid phase crackingconditions in the presence of a reforming catalyst of silicious contentat a temperature selected betweenthe limits of 300 C. and 500 C.;unveiling toxicity in the materials under treatment by continuing thenamed cracking operation for a period not in excess oi. about .twohours, the period being so selected with reference to the chosentemperatureand pressure as to provide a percentage of newly inducedmaterials boiling below 210 C. falling between the limits of 10-50%;securing the unveiled toxicity in a relatively high degree byacoordination of time, temperature and pressure which provides less thanabout 30% but more than about 5% saturates in the beneficiated materialboiling between 270 C. and 355 C. whereby to provide an overallbeneficiated material having substantial residual matter above 315 C.and a toxicity in excess of the starting material; and segregating fromthe beneficiated material an oil of the wood preservative type havinginduced toxicity and an initial boiling'point at, least as low as about270 C., substantial residual materials boiling above 315 C., and an endboiling point at least as high as about 355 C., the fraction 270-355 C.of the segregation having a percentage of saturates falling between thelimits above named.

8. The process of claim '7 with inclusion of carrying on the crackingoperation in the presence of a protective gas of extraneous source.

9. A wood preserving impregnant consisting in its entirety of a mixtureof cracked petroleum fractions having less than about 30% but more thanabout 5% saturates in the materials boiling between 270355 C.,;an.initial boilin point at least as low as about 270 C., a'final boilingpoint above 355 C. and not less than about 45% boiling up to 355 C. andsubstantial residual material above 315 C.

10. A wood preserving impregnant consisting

